Personally i would do a simple interrogation. Something along the lines of " make yourself known, identify yourself in a manner i will recognize or kindly get the hell out!! You are wasting my time and yours!" Next time you sense um.
But im a punky bastard 
i dont scare easy.
Last time i have done this i got all kinds of info related to Rahu dropped on my head lol. (Reptilian rabbit hole related)
yep i dont scare easily too, i actually saw a guy smiling 2 days before that day, he was smiling to me he was old and he was like an translucent image floating in the air and i really didnt have fear i feeled anger and i decided to touch him and he disappeared when i touched him, i never used drugs in my life but i have plans to have a little trip with dmt!
Well then next time interrogate his ass lol no one has time for this ghost routine lmao i make this VERY clear when anything tries to show up uninvited. It either makes itself know or may become lunch xD
Due to mixing demons with angels and elementals for my workings this month, it could pass for Heheheel, a zodiac angel (moon in Aquarius), except for his colors - violet and yellow, and blue and orange. "Heheheel is seen as a vibrant, fiery and active man with ram horns. He has red hair and eyes and stands on flames. He holds a royal sceptre of dominion and holds a royal orb."
However, you’ve been seeing the original Norse dude for eleven years … So this is probably not Heheheel.
Or could be another one I evoked for work, a zodiac angel named Vavalaiah, Saturn in Pisces.
"Vavalaiah appears as a man with the head of a horned bull. He is tall and strong and holds a pastoral staff. He stands above the clouds."
But again, eleven years is a lot longer than a month.
i saw him once only, and the day i saw him cant remeber wich month but it was in a range from march to september
But eleven years ago?
yes
Yeah … Wouldn’t have been my recent work, my bad.
Oh no.Nononononono.
I have had quite enough of that skull dugery 
i was just makin my point. Again Rahu
I mayyy work with him later down the line 
if he doesnt already have connections to one of the divs. May explore this later but i have enough to keep busy with for at least the next year at this point lmao. 
No, you don’t understand. It’s not you. It’s me. I’m waiting for something and you’re confirming it. Big time.
Ohhh okay then i would suggest exploring Rahu also known as Rahu Ketu. From my current understanding, In vedic astrology he is tied to both those things that have already been mastered in past lives and those things we never get enough of.
mm about the simbol i saw it seems that could be from lilith since i was searching info about lilith and i found that the kolovrat is about fertility and agriculture and lilith is know for being the godess of fertility and agriculture in ancient sumeria!?!?